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    <meta charset="UTF-8">
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    <title>返回当前的文件和链接的文档之间的关系</title>
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<body>
    <p><a id="func" rel="friend" href="//www.functravel.com/">优惠航班</a></p>
    <script>
        document.write("当前文档和连接的文档之间的关系: ");
        document.write(document.getElementById("func").rel);
    </script>
</body>

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